Sparking plug



Sepa. is, w23.

P; D. PETERSON SPARKING PLUG Filed Feb 1 1921 Patented ept. 118 15923.

it WEE@ atacar* SPARKING PLUG.

Application led February 1, 1921. Serial No. 441,827.

To all whom it may concern.:

Be it known that I, PER DAN Pnrnnsol, a citizen of the Kingdom of Sweden, residing at Lidkoping, Sweden, have invented new and useful Improvements in Sparking Plugs, of which the following is a spec1cation.

This invention relates to sparking plugs of the kind in which the sparking points are enclosed within an explosion chamber provided at the inner end of the sparking plug and communicating with the combustion chamber of the engine for which the sparking plug is used.

One object of the invention is to so arrange the sparking points as to automatically maintain the latter free from deposltsy of carbon as well as from incrustation of carbonized oil, which would otherwise prevent 4the formation of the spark. To this end one of the electrodes consists of a central rod, while the other electrode consists of a clip mounted below the lower end of the said rod.

Another object of the invention relating to the above said object is to provide a sparking plug in which the said clip may be readily replaced by unscrewing the parts. To this end the said clip is lll-shaped and has its side portions formed with upwardly directed extensions the ends of which are bent and clamped between the insulating tube and the metallic casing of the sparking plug.

The invention is illustrated in the accom# panying drawing, which shows one embodiment thereof. Fig. 1 is a side elevation and Fig. 2 is a central, longitudinal section of the sparking plug.

With reference to the drawing, the numeral 1 denotes a metallic casing formed to shape a nut 20 at its upper portion, said casing having at its lower end external screw-threads 5 by means of which the plug is screwed into the cylinder of the motor in the usual way. The casing is formed with a boring the upper portion of which has a greater diameter than that of the lower portion of the boring so as to form a shoulder 2 between the said two portions Vof the boring. The upper wider portion of the boring is formed with inner screw-threads 3. Resting on the shoulder 2 is an insulating tube 4, preferably made of porcelain, said tube being held in place in the boring by means of a nut 6 screwed into the threads 3 and resting on a shoulder 7 formed on the insulating tube 4. Between the insulating tube and the knut 6 l may place a resilient ring 8, for instance, one made of copper, and between the insulating tube and the shoulder 2 there may be inserted a similar ring 9. The insulating tube is formed with a centrally, through-extending boring 10 for the reception of an electrode rod 11, said electrode rod being adjusted and maintained in desired position by means of nuts 13 and 14, screwed on the rod 11 at opposite ends of the insulating tube 4. The casing 1 is provided with a perforated bottom 15 at its lower end, said bottom being secured to the casing by means of columns 16, so as to form an open explosion chamber 17 at the lower end of the plug to enclose the sparking points of the electrodes.

The electrode cooperating with the inner point of the rod 11 consists of a clip 18, preferably made from copper, nickel, or any other appropriate metal. shaped and has the upper bent ends of its side-portions clamped between the shoulder 2 and the insulating tube 4 or-the ring 9. The rod 11 is adjustable in the usual way so as to permit its inner end to be adjusted at any distance desired from the clip 18.

By the arrangement of the electrodes as above described the eifect will be obtained that the sparking point formed by the curved portion of the maintain itself free from deposit of carbon, incrustation of carbonized oil or the like, the explosions will eject such impurities from the explosion chamber containing the sparking points. Furthermore, the sparking plug ma be repaired readily and at low costs by rep acing the clip 18 and adjusting the rod 11.

What I claim is A spark plug comprising an insulating tube having an axial bore enlarged at its lower end to form a chamber, a metallic casing surrounding the tube and extending beclip 18 will alwaysl rlhe clip 18 is'U- low the lower end of the latter and forming I titille having its ends olampefl; between co-l i of the latter, the central portion of the U-y 5 shaped electrode being curved toward the end of the rod-shaped electrode and extending into the c'hambenend a cover connected moslim to the lower end of the casing having o. central aperture therein and forming an open explosion chamber at the lower' end of t 10 casing.

In testimony whereof have 'signed my Pm' MN Pn'mnson. 

